I don’t think its about how he reacted but rather how author portrayed a trans person. It’s a minority community but they had to make the assaulter, in other words side “evil” npc, a trans woman. Trans women especially get so much fetishized and seing it in a gay comic is understandably upsetting imo
I'm not korean but from what I see and heard, korea is still mostly conservative country especially with trans and rarely are accepting of them yet. In their showbiz trans people are very rare to see that in squid game season 2, the trans character had to be portrayed by a straight albeit a very talented actor because the director admitted they couldn't find a trans actor that fits the character even if he wanted to cast one
I guess thats why the author also had the use a trans char this way to elicit uncomfortable feeling to their korean readers
i dont think its transphobia to be surprised at genitals you arent expecting while youre getting assaulted